I had to treat my betta, Rakki, for a fungal infection a couple of months ago, and I think I might have to do it again. I noticed a small white fuzzy patch hanging from one of his ventral fins a few days ago. It's still there after his water change yesterday.

My fiance and I... got a little lazy about the water changes for his 1-gallon bowl. I feel absolutely terrible that he seems to have gotten sick again because of our lapse in keeping to our water change schedule.

I was wondering if we should try just changing his water 100% every day for a few days first, or if we should go ahead and start with the 100% water changes + 1 tsp. of aquarium salt tomorrow.

Here's the information I know I need to fill out:

Housing
What size is your tank? 1 gallon bowl
What temperature is your tank? About 74 or 75 degrees Fahrenheit
Does your tank have a filter? No
Does your tank have an air stone or other type of aeration? No
Is your tank heated? No
What tank mates does your betta fish live with? None

Food
What type of food do you feed your betta fish? Omega One pellets (recently switched from Aquarian pellets)
How often do you feed your betta fish? 2 pellets twice a day
Maintenance
How often do you perform a water change? 2 100% water changes per week, but we've gotten lazy recently, so it's been more like 1 100% per week. (I feel so bad!)
What percentage of the water do you change when you perform a water change? 100%
What type of additives do you add to the water when you perform a water change? Tetra BettaSafe water conditioner

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? A small fuzzy white patch showed up on his ventral fin a few days ago.
How has your betta fish's behavior changed? He's actually been more active since we switched to the Omega One pellets
When did you start noticing the symptoms? Last Friday (the 16th)
Have you started treating your fish? If so, how? Not yet.Does your fish have any history of being ill? He had a fungal infection once before which was successfully treated with aquarium salt and water changes. Other than that and a couple incidences of tail-biting, he's been pretty healthy.
How old is your fish (approximately)? We've had him since the middle of April of this year. He's an adult.

Go with changing the water first and see if that helps him improve; sometimes all a betta needs is some nice clean water to be feeling better. Since it sounds like he's still energetic I would hold off on adding the aquarium salt after doing a couple 100% water changes.

Rakki wasn't looking any better with just the water changes, so we started with the aquarium salt last night. His ventral fin is looking a lot better already. I can't even see the fuzzy white patch anymore. We're going to continue with the salt for tonight and tomorrow to make sure it stays gone. Is that enough time since it wasn't a bad infection and we caught it early? Just want to make sure it stays gone.

You may want to do it for a couple days longer than that, or else do the aq. salt treatment today and tomorrow and then just make sure he has 100% water changes to really get rid of the white patches and make sure whatever it is doesn't reproduce in any way in the water.

I ended up at the same conclusion after my last post, especially when I looked at Rakki again more closely and still saw a small, almost-invisible bit of the fuzzy stuff on his ventral fin. We'll probably treat him for a week to make sure we get rid of it. Thanks for the replies and advice.